The Jews came no short in their enmity, and using all the means they had against the prophet, such as military invasion - economical incursion - social attack - and this verse points to a corner of their cultural rush: ``And a party of the people of the Book said: ` Believe in that which is sent to the believers in the morning, and deny it at evening, perhaps they may return.'' Their plan was not without effect at least on some of the weak minded Muslims and those wanting self - reliance, because the 12 Jews who hatched the plot were known for knowledge and being well versed in the Bible.